The Dominant Seventh Pentatonic is an underrated scale in my humble opinion, but you can use it with excellent results in Blues contexts and in numerous modern ones.

First of all, let's recap the intervals:

Root, 2nd, 3rd, 5th 7th minor.

If we were in C dominant 7th pentatonic we have: C D E G Bb

As you can see it's derived from Mixolydian Scale without the 4th and the 6th,

Here's the fingering:

I wrote a couple of licks for you to let you understand its sound better:

On C7 again:

Interesting, isn't it?

A less tradition applies, that I personally consider much more interesting than the first one, could be to use this scale over a minor seven chord.

For instance: use C Dominant Seventh Pentatonic over G min7. Why? Let's consider Gmin7 as II grade of F Major, so it's like you used C Mixolydian over Gmin7. You can add some cool chord extensions with that.

A few licks over Gmin7:

And again:

You can find all this on my new course "Scale Concepts For Modern Blues Guitar"